/*
 * Copyright (c) 2005 Brian Goetz and Tim Peierls
 * Released under the Creative Commons Attribution License
 *   (http://creativecommons.org/licenses/by/2.5)
 * Official home: http://www.jcip.net
 *
 * Any republication or derived work distributed in source code form
 * must include this copyright and license notice.
 */

package io.github.dunwu.javacore.concurrent.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * The field or method to which this annotation is applied can only be accessed when holding a particular lock, which
 * may be a built-in (synchronization) lock, or may be an explicit java.util.concurrent.Lock.
 * <p>
 * The argument determines which lock guards the annotated field or method:
 * <ul>
 * <li><code>this</code> : The intrinsic lock of the object in whose class the field is
 * defined.</li>
 * <li><code>class-name.this</code> : For inner classes, it may be necessary to
 * disambiguate 'this'; the <em>class-name.this</em> designation allows you to specify
 * which 'this' reference is intended</li>
 * <li><code>itself</code> : For reference fields only; the object to which the field
 * refers.</li>
 * <li><code>field-name</code> : The lock object is referenced by the (instance or static)
 * field specified by <em>field-name</em>.</li>
 * <li><code>class-name.field-name</code> : The lock object is reference by the static
 * field specified by <em>class-name.field-name</em>.</li>
 * <li><code>method-name()</code> : The lock object is returned by calling the named
 * nil-ary method.</li>
 * <li><code>class-name.class</code> : The Class object for the specified class should be
 * used as the lock object.</li>
 */
@Target({ ElementType.FIELD, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface GuardedBy {

    String value();

}
